Setting up my timing
 

The other week i had a few parts zinc plated and had to remove the distributor; stupidly I did not make any markings on the distributor so i could simply place it back in the same position. So now i am unsure of the procedure to set the timing right on my baby. It's an 83 SC engine. Any help would be greatly appriciated. Thank You

911911,

The procedure is the same for just about all cars – even a Porsche. Simply find when piston #1 is at TDC at the end of its compression stroke, and line up the rotor so that it points at plug wire #1 position on the distributor. Here are the specifics:

You must find when piston #1 is coming to the top of its compressions stroke. This is where most people make a mistake. Piston #1 comes to the top of its stroke twice – once at the end of the exhaust stroke, and once at the end of the compression stroke. When the timing mark on the pulley shows Z1 at the top, piston #1 is also at the top of its stroke – the question is, which stroke? The exhaust stroke or the compression stroke? There are a couple of ways to ensure that piston #1 is on its compression stroke. One way is to remove the upper and lower valve covers, and make sure both the intake and exhaust rocker arms are loose – that there is no load on them. If piston #1 is on the end of the exhaust stroke, the exhaust rocker would be pushing on the valve, and not be loose. Due to valve overlap, the intake will also be opening in this position, and the rocker will be tight. This information can allow you to only remove the upper valve cover, and avoid removing the lower valve cover and making an oily mess. You can turn the engine over and notice when the intake rocker for #1 is slack, and when it is loaded. This will tell you when piston #1 is on its intake stroke (intake rocker loaded), and when you just passed TDC at the end of the compressions stroke (intake rocker loose for about ½ a crankshaft rotation).

You can also take a piece of tubing, and screw one end into the spark plug hole, and when you turn the engine over, on the compression stroke, you will feel pressure in the tube if you hold your thumb over the other end of the tube. Turn the engine over until you feel the pressure, then stop when Z1 is up and lined up with the engine parting line.

I don’t recommend ever putting anything into the sparkplug hole to feel when the piston is coming up or going down – too many horror stories about things breaking off in the cylinders.

Now that you have piston #1 at TDC at the end of the compression stroke, insert the distributor so that the rotor points to plug wire #1 position on the distributor cap. To do this, put the cap on the distributor, and see if there is already a mark on the distributor where plug wire #1 position is. If there is not, make a mark with a pencil or a piece of tape. When you insert the distributor, note that the drive gear on the bottom of the distributor causes the distributor to turn slightly as you install it. Install the distributor so that the rotor ends up pointing at the mark you made for #1 spark plug position, and the distributor body sits in the middle of the timing adjustment (the slot where the distributor hold down bolt is).

Just snug up the hold down bolt and see if the car will start. Once the car starts, you can check the timing with a timing light. I like to use a dial in timing light to make setting the total timing easier. Your timing specification is usually shown at both idle (initial timing) and at 6000 RPM (total timing). It should also say whether the vacuum advance and or retard is connected or disconnected. One nice thing about setting the total timing at 6000 RPM is that it doesn’t matter if the vacuum is connected or not – the engine doesn’t have much vacuum when the throttle is opened this far. First set your initial timing at idle – rotate the distributor until you get close to where the initial timing spec is for your car. Now set your timing light to the total timing spec – about 35 to 38 degrees. With the car idling, line up your light on the timing pulley and then rev the engine. You will see the timing marks advance and then stop (if your advance is working correctly) and let the engine return to idle. Where the advance stopped is the total timing. If this isn’t at the 35 to 38 degrees desired, rotate the distributor slightly and try it again. You shouldn’t have to sit at 6000 RPM, just rev the engine quickly and note where the timing stops advancing. Rotate the distributor at idle and try again until you get the total advance desired – regardless of where the initial timing ends up. The total timing is the more important setting to maximize acceleration.

Remember that the 83 SC 3.0L has a distributor that turns counterclockwise.

Line the rotor up with the notch on the distributor body that is about at 2 o'clock. You might have to take the dust shield off.

Crank the motor till it is at the notch before Z1, or the first of the two that are close together.

Then bolt the distributor right in. If the motor doesn't fire up, then take the distributor out, and re-turn the crank again 360 degrees, and the re-insert and try it again. When you put the distributor in, be sure not to force it or you could crack the distributor. The teeth can be wiggled a little, and since the gears are sort of a curved worm gear, the distributor can turn as much as 10 or 15 degrees, so you may have to try it a few times to get the hang of it.

thank you for your help. I read your post's and found a good article in the tech info centre, and car fired up first go. i now need to get my hands on a timing light and set the idle. Thank you both for your help!